The challenges of modern car batteries

[Micael]

So I had my leased car in for service and promptly got a notification that they’d tested the battery and it had a fault, needing to be replaced and would I sign off on a battery change for about $500. Certainly not, excessive for that job. Mind you the car is two years old so the OEM battery going bad so quickly is…interesting.

Anyway, instead began my journey to figuring out what battery the car should have. It is a Seat Ibiza, which is a Volkswagen Automotive Group brand, and essentially a Volkswagen Polo in disguise. Is it possible to find the information in any manual, online service or the like provided by VAG? Of course not. Is it possible to find out what battery is in it now by just opening the hood and looking at it? Of course not as VAG has integrated some sort of cover with the positive lead and this covers the top of the battery which is where the OEM ones have the information written, meaning you have to disconnect it before you can read it. Well I didn’t fancy doing that before I had a new battery at hand just in case the old battery would decide to give up for good if I disconnected and then reconnected it, leaving me with a stranded car. After some online sleuthing I did figure out what size and type should be in it. An oddly sized variant which wasn’t available in too many places without ordering it in advance, but I did find one place that had a single Exide 55 Ah EFB model of the correct size in stock for about $100. 55 Ah seemed a tad on the weak side to me but the online enquiries had suggested that it’d be okay. That it had to be an EFB was a given since the car is forced to have that annoying start-stop function on it. So I got the battery, managed to get the leads off the old one (not a massive amount of space available to work with) and found that the OEM battery was a Varta EFB one, with only 49 Ah. Now that seems very low in capacity to me. In any case I managed to extract the old battery and insert the new despite minute tolerances (remove bracket, push forward, tilt sideways and somehow rotate it past the aforementioned cover with minimal lenght leads to be able to lift it out, sans handle).

But I suspect that some of you here know more about these things than I do, is 49 Ah on the low side for a car with a start-stop function and the modern electronics suite? Could that be why it only lasted two years? I have a sneaky suspicion that maybe VAG is putting in as low capacity a battery as possible, so the dealers can rack up easy battery replacement charges more frequently.

[warshipadmin]

Yup 49 is a tiny battery for a car. Batteries in general are a problem for OEMs, they are heavy, unreliable, easy to steal, often broken before they get to the factory.

Conspiracy theories about deliberately designing the car to be hard to repair are common on the interwebz, I've never heard of a direction to do so when designing subsystems. We actually track Total Cost of Ownership, including servicing and repairs, for the fleet buyers.

[Paul Nuttall]

That it had to be an EFB was a given since the car is forced to have that annoying start-stop function on it.
But I suspect that some of you here know more about these things than I do, is 49 Ah on the low side for a car with a start-stop function and the modern electronics suite? Could that be why it only lasted two years? I have a sneaky suspicion that maybe VAG is putting in as low capacity a battery as possible, so the dealers can rack up easy battery replacement charges more frequently.

Doesn't it have a button to turn off the stop start function?

[Micael]

Yup 49 is a tiny battery for a car. Batteries in general are a problem for OEMs, they are heavy, unreliable, easy to steal, often broken before they get to the factory.

Conspiracy theories about deliberately designing the car to be hard to repair are common on the interwebz, I've never heard of a direction to do so when designing subsystems. We actually track Total Cost of Ownership, including servicing and repairs, for the fleet buyers.

Thanks. Well it isn’t as easy as older cars in any case. I miss my Volvo 740 sometimes.

[Micael]

That it had to be an EFB was a given since the car is forced to have that annoying start-stop function on it.
But I suspect that some of you here know more about these things than I do, is 49 Ah on the low side for a car with a start-stop function and the modern electronics suite? Could that be why it only lasted two years? I have a sneaky suspicion that maybe VAG is putting in as low capacity a battery as possible, so the dealers can rack up easy battery replacement charges more frequently.

Doesn't it have a button to turn off the stop start function?

It does, and it’s actually a physical button on this model, but it resets every time you turn off the engine, and sometimes I forget to turn it off.

[Nik_SpeakerToCats]

"... deliberately designing the car to be hard to repair ..."

Sometimes, gotta wonder...
Especially with CAD/CAM allowing full 3-D Solid Modelling, so such 'Oopsies' should have been caught.

I remember a local 'parts factor' jacking up a 'Euro city car', removing wheel and horn to provide clearance to remove battery to provide clearance to replace head-light multi-bulb.

The bulb swap took seconds.
Getting to it, though...

IIRC, even the Haynes Manual recommended this approach.
--
Tangential, the first evening we had my beloved wife's red Skoda Motability car, I spent hours searching the 'User Handbooks' (plural !!) trying to find the jacking points, screen-wash tank access and other useful stuff.

D'uh, just getting the hood/bonnet open was fraught because, though 'English' text for RHD, most illustrations were for LHD...

There were about 120 pages in the first book, ~150 in second which was mostly about the 'edutainment' facilities.
Neither were multilingual, but both were 'American Indexed', such you had to know *exactly* what they called a topic to find it.

There was NO cross-referencing or allowance for vernacular, nor 'Quick Access' per 'HELP ! I HAVE A PROBLEM !!'

For the record, all necessary info was tucked away under utterly anonymous titles near the back of first book.
Impossible to find in a hurry...

[gtg947h]

"... deliberately designing the car to be hard to repair ..."

Sometimes, gotta wonder...
Especially with CAD/CAM allowing full 3-D Solid Modelling, so such 'Oopsies' should have been caught.

"Whatever is fastest/cheapest to assemble" probably dwarfs concerns about serviceability, as do things like styling, aerodynamics (for fuel efficiency compliance) etc. If it makes it harder to service, they won't care. The engineers may complain (assuming they have full visibility into all the design at once, which I'm betting they mostly don't).

But the idea of "reduce user serviceability" is very real in automotive and many other fields (industrial machinery for one). Users doing less themselves means more work for your service department. I saw a video years ago of some German car where they made it deliberately difficult to just pop the hood, let alone open it without breaking something.

If I had "F you money" or a rich sugar daddy, I'd probably start something designing open-source appliances you could make and maintain from a combination of common industrial components from McMaster, Digikey, etc and printed, hand-cut, and/or shopped (e.g. SendCutSend) fabrication.

I very much prefer to do whatever I can myself, and the very concept of planned obsolescence pisses me off both personally and professionally as an engineer.

[Craiglxviii]

Nemiga is your friend..!!!

[Micael]

I should also add that it was time to change out the wipers, they wanted a bit over $140 to do that. Bought new ones for about $23 and swapped those out myself in about 20 seconds. Equally ludicrous overcharge. The battery swap took 20 minutes mostly because I didn’t want to risk breaking any of the annoying plastic pieces along the way, now that I know how everything fits together and have done it once I think I could get it down to under 10, less if I do it a few times. Absurd upcharge by the dealer for a minimal amount of actual labour. I shudder to think what it’d cost if I had to get something more complicated repaired.

[Sukhoiman]

It has been relative monopoly/monopsony kind of thing for decades now when its "the dealer" when its labour. A significant chokepoint (ok we will get to it "in our scheduling/backlog" and charge you for all of that) and thus premium. It sets the highwater mark for other service providers in other garages to price close to that too...everyone kind of knows they are a chokepoint and enough ppl will fork away the price asked with little second thought.

It wont change....so yes do the acquire + labour wherever possible yourself.

[Craiglxviii]

I should also add that it was time to change out the wipers, they wanted a bit over $140 to do that. Bought new ones for about $23 and swapped those out myself in about 20 seconds. Equally ludicrous overcharge. The battery swap took 20 minutes mostly because I didn’t want to risk breaking any of the annoying plastic pieces along the way, now that I know how everything fits together and have done it once I think I could get it down to under 10, less if I do it a few times. Absurd upcharge by the dealer for a minimal amount of actual labour. I shudder to think what it’d cost if I had to get something more complicated repaired.

It would cost you €150/hr plus 300% margin typically!

[Micael]

I should also add that it was time to change out the wipers, they wanted a bit over $140 to do that. Bought new ones for about $23 and swapped those out myself in about 20 seconds. Equally ludicrous overcharge. The battery swap took 20 minutes mostly because I didn’t want to risk breaking any of the annoying plastic pieces along the way, now that I know how everything fits together and have done it once I think I could get it down to under 10, less if I do it a few times. Absurd upcharge by the dealer for a minimal amount of actual labour. I shudder to think what it’d cost if I had to get something more complicated repaired.

It would cost you €150/hr plus 300% margin typically!

Madness.

[warshipadmin]

"Especially with CAD/CAM allowing full 3-D Solid Modelling, so such 'Oopsies' should have been caught."

Best practice, widely ignored is to reuse 70% of the components in a new car design. So if you can reuse a component from a different car then it is likely to be used even if it causes some hassle with assembly. You save on designing it, getting quotes, prototyping, some testing and possibly validation. You don't need to stock it separately. You don't need a new part number. Part numbers cost money. This especially applies if it is not a part that is expected to wear out in the warranty period.

As to catching assembly problems in CAD, yes these days it is done, firstly each fastener has an access volume for tools, and then they actually animate the assembly process.

[Nightwatch2]

Yup 49 is a tiny battery for a car. Batteries in general are a problem for OEMs, they are heavy, unreliable, easy to steal, often broken before they get to the factory.

Conspiracy theories about deliberately designing the car to be hard to repair are common on the interwebz, I've never heard of a direction to do so when designing subsystems. We actually track Total Cost of Ownership, including servicing and repairs, for the fleet buyers.

how does AH equate to CCA (Cold Crank Amps)

you all seem to be measuring it differently than we do.

[warshipadmin]

They are different. Ah is the capacity (amount of charge) it can hold, whereas CCA is the current it can supply at -18 deg C for 30s without falling below 7.2V, which is typically where the ECU drops out. A car battery typically has a high CCA and a fairly low Ah, whereas my off grid batteries are designed for high Ah, and CCA doesn't matter, 60A would be unusual.

A starter motor needs 150-300A in warm weather, I don't know what it needs in cold weather.

[kdahm]

Yup 49 is a tiny battery for a car. Batteries in general are a problem for OEMs, they are heavy, unreliable, easy to steal, often broken before they get to the factory.

Conspiracy theories about deliberately designing the car to be hard to repair are common on the interwebz, I've never heard of a direction to do so when designing subsystems. We actually track Total Cost of Ownership, including servicing and repairs, for the fleet buyers.

how does AH equate to CCA (Cold Crank Amps)

you all seem to be measuring it differently than we do.

Amp-hours is the quantity of possible electricity in the battery. Consider it the amount of fuel in the tank.

Cold Cranking Amps is the rate at which the battery can deliver that energy when not worm, something like 32F or 0F depending on how the manufacturer defines it. That's more like the power of the engines at sea level.

Large AH rating at a low CCA, if that's defined for that battery, is mom's econobox with the entire rear taken up by auxiliary gas tanks. It'll get from Chicago to Seattle without stopping for gas, but it'll take a while to get there.

Low AH at high CCA is essentially a top fuel dragster. It'll get to where it's going fast, but only if that place is within 3000 meters or it'll run out of gas. Somebody just did that with a desktop, using 56 AA batteries and getting one round of Minesweeper at five minutes before the batteries died.

Hope this helps.

[Nightwatch2]

Yup 49 is a tiny battery for a car. Batteries in general are a problem for OEMs, they are heavy, unreliable, easy to steal, often broken before they get to the factory.

Conspiracy theories about deliberately designing the car to be hard to repair are common on the interwebz, I've never heard of a direction to do so when designing subsystems. We actually track Total Cost of Ownership, including servicing and repairs, for the fleet buyers.

how does AH equate to CCA (Cold Crank Amps)

you all seem to be measuring it differently than we do.

Amp-hours is the quantity of possible electricity in the battery. Consider it the amount of fuel in the tank.

Cold Cranking Amps is the rate at which the battery can deliver that energy when not worm, something like 32F or 0F depending on how the manufacturer defines it. That's more like the power of the engines at sea level.

Large AH rating at a low CCA, if that's defined for that battery, is mom's econobox with the entire rear taken up by auxiliary gas tanks. It'll get from Chicago to Seattle without stopping for gas, but it'll take a while to get there.

Low AH at high CCA is essentially a top fuel dragster. It'll get to where it's going fast, but only if that place is within 3000 meters or it'll run out of gas. Somebody just did that with a desktop, using 56 AA batteries and getting one round of Minesweeper at five minutes before the batteries died.

Hope this helps.

Helps a lot, thanks. And makes perfect sense.

But not how they are sold here.

What’s interesting is that when I go to the car parts store for a battery, all I get is the CCA rating. I’ve never ever seen the AH rating. And the batteries here are about one hundred $.

Probably rated that way because all you need it to do is start the car. After that it’s on the alternator to keep it running.

[Micael]

how does AH equate to CCA (Cold Crank Amps)

you all seem to be measuring it differently than we do.

Amp-hours is the quantity of possible electricity in the battery. Consider it the amount of fuel in the tank.

Cold Cranking Amps is the rate at which the battery can deliver that energy when not worm, something like 32F or 0F depending on how the manufacturer defines it. That's more like the power of the engines at sea level.

Large AH rating at a low CCA, if that's defined for that battery, is mom's econobox with the entire rear taken up by auxiliary gas tanks. It'll get from Chicago to Seattle without stopping for gas, but it'll take a while to get there.

Low AH at high CCA is essentially a top fuel dragster. It'll get to where it's going fast, but only if that place is within 3000 meters or it'll run out of gas. Somebody just did that with a desktop, using 56 AA batteries and getting one round of Minesweeper at five minutes before the batteries died.

Hope this helps.

Helps a lot, thanks. And makes perfect sense.

But not how they are sold here.

What’s interesting is that when I go to the car parts store for a battery, all I get is the CCA rating. I’ve never ever seen the AH rating. And the batteries here are about one hundred $.

Probably rated that way because all you need it to do is start the car. After that it’s on the alternator to keep it running.

The CCA is 540 on the new battery that I got. You’ll see it listed here as well but I think that for most cars on the road here more or less every battery will have enough CCA, it’s more if you get to large engines like a classic V8 and stuff that I’d personally start to look very carefully at the CCA. The Ah matters a bit more to me as it gives an indication of how frequently it can perform a start without having had time to be fully recharged in between. So if you normally drive very short distances it becomes of particular interest. With the new cars with the start-stop thingy it matters more as well, but then you also need it to be either an EFB one (more expensive that a regular battery) or an AGM one (even better but also even more expensive). These can do more discharge/charge cycles than a traditional battery before going bad.

[Nightwatch2]

Amp-hours is the quantity of possible electricity in the battery. Consider it the amount of fuel in the tank.

Cold Cranking Amps is the rate at which the battery can deliver that energy when not worm, something like 32F or 0F depending on how the manufacturer defines it. That's more like the power of the engines at sea level.

Large AH rating at a low CCA, if that's defined for that battery, is mom's econobox with the entire rear taken up by auxiliary gas tanks. It'll get from Chicago to Seattle without stopping for gas, but it'll take a while to get there.

Low AH at high CCA is essentially a top fuel dragster. It'll get to where it's going fast, but only if that place is within 3000 meters or it'll run out of gas. Somebody just did that with a desktop, using 56 AA batteries and getting one round of Minesweeper at five minutes before the batteries died.

Hope this helps.

Helps a lot, thanks. And makes perfect sense.

But not how they are sold here.

What’s interesting is that when I go to the car parts store for a battery, all I get is the CCA rating. I’ve never ever seen the AH rating. And the batteries here are about one hundred $.

Probably rated that way because all you need it to do is start the car. After that it’s on the alternator to keep it running.

The CCA is 540 on the new battery that I got. You’ll see it listed here as well but I think that for most cars on the road here more or less every battery will have enough CCA, it’s more if you get to large engines like a classic V8 and stuff that I’d personally start to look very carefully at the CCA. The Ah matters a bit more to me as it gives an indication of how frequently it can perform a start without having had time to be fully recharged in between. So if you normally drive very short distances it becomes of particular interest. With the new cars with the start-stop thingy it matters more as well, but then you also need it to be either an EFB one (more expensive that a regular battery) or an AGM one (even better but also even more expensive). These can do more discharge/charge cycles than a traditional battery before going bad.

Yep, understand all. That’s just a capacity measurement that I have not seen used over here.

540 CCA is pretty decent. That should handle a car pretty well.

[Nik_SpeakerToCats]

This is why RVs often have *two* batteries of oft-similar appearance and nominal AH capacity but very different internals.

The 'vehicle' has huge CCA-provider for 'cold start on a cold day' or 'jump start' cranking.
The 'recreational', like 'off-grid' battery, provides for steady loads: Often sealed 'SLA', best fused to shun CCA stuff.

I've heard of RVs / Motor-homes whose alternators died using 'recreational' to keep vehicle going after 'CCA' start...